Effect of K on nitrogen fixation of intercrop groundnut and the competition between intercrop groundnut and maize

Application of adequate level of K has shown to improve the competitive ability of the legume in legume/grass mixtures. However, the effect of K on the competitive ability of grain legumes in legume/cereal intercropping systems has not been adequately studied. Hence, studies were made to ascertain if the effects of K could be exploited in improving the performance of groundnut (Arachis hypogaea L.) cv. No. 45 when intercropped with maize (Zea mays L.) cv. Badra. The study was conducted at the Faculty of Agriculture, University of Ruhuna, Kamburupitiya, Sri Lanka in 1988 in basins filled with 36 kg of soil. It involved establishing maize and groundnut as monocrops and as intercrops at three K levels viz. 0, 20 and 40 mg of K kg^–1 of soil. Monocrop maize and groundnut had 2 and 5 plants/basin, respectively while the intercrop had 1 maize plant and 3 groundnut plants/basin. The soil used was Red Yellow Podzolic which was tagged by incorporating¹⁵N-labelled plant material. When grown as a monocrop, K had no effect on the percent N derived from atmosphere, amount of N₂ fixed, dry matter production, pod yield and total N content of groundnut. However, when intercropped with maize lack of K application affected the above parameters significantly which was overcome by improving K level. Thus, the optimum level of K for groundnut was greater when intercropped than monocropped. A significant interaction between K level and cropping system was evident with regard to N₂ fixation, pod yield and total dry matter production of groundnut. Intercrop maize derived 30–35% of its N content from the associated groundnut plants which amounted to 13–22 mg N/plant. The amount of N supplied by groundnut to associated maize plant was not affected by K level. It appears that there is scope for alleviating growth depression of the legume component in legume/cereal intercropping systems by developing appropriate K fertilizer practices.     

Large pressure depression of methane hydrate by adding 1,1-dimethylcyclohexane

The structure-H hydrate of 1,1-dimethylcyclohexane (DMCH) helped by methane has been investigated in a temperature range of 274.6-289.3 K and pressure range up to 6.7 MPa. The present results suggest that 1,1-DMCH is a suitable additive which makes a mild-pressure handling of natural-gas hydrate possible.     

多磁路变压器的应用与调节系统的改进

介绍了多磁路变压器的工作特点、输出能力和过电压的抑制。提出采用多级变压与分配控制和辅助调节器的改进电压调节系统，可提高其稳定性在任一电压阶梯内获得无级线性调节。     

Reducing depression among at-risk early adolescents: Three-year effects of a family-centered intervention embedded within schools.

The Adolescent Transitions Program (ATP) is a family-focused multilevel prevention program designed for delivery within public middle schools to target parenting factors related to the development of behavior problems in early adolescence. The current study examines the effects of the ATP on the development of youth depressive symptoms across early adolescence in a sample of 106 high-risk youths. Youths were recruited in 6th grade, and selected as high risk based on teacher and parent reports of behavioral or emotional problems. Depression symptoms were based on youth and mother reports in 7th, 8th, and 9th grades. Receipt of the family-centered intervention inhibited growth in depressive symptoms in high-risk youths over the 3 yearly assessments compared with symptoms in high-risk youths in the control group. Results support the notion that parental engagement in a program designed to improve parent management practices and parent-adolescent relationships can result in collateral benefits to the youths' depressive symptoms at a critical transition period of social and emotional development. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Positive psychotherapy.

Positive psychotherapy (PPT) contrasts with standard interventions for depression by increasing positive emotion, engagement, and meaning rather than directly targeting depressive symptoms. The authors have tested the effects of these interventions in a variety of settings. In informal student and clinical settings, people not uncommonly reported them to be "life-changing." Delivered on the Web, positive psychology exercises relieved depressive symptoms for at least 6 months compared with placebo interventions, the effects of which lasted less than a week. In severe depression, the effects of these Web exercises were particularly striking. This address reports two preliminary studies: In the first, PPT delivered to groups significantly decreased levels of mild-to-moderate depression through 1-year follow-up. In the second, PPT delivered to individuals produced higher remission rates than did treatment as usual and treatment as usual plus medication among outpatients with major depressive disorder. Together, these studies suggest that treatments for depression may usefully be supplemented by exercises that explicitly increase positive emotion, engagement, and meaning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Grandparents' psychological well-being after loss of contact with their grandchildren.

This study examined how loss of contact with grandchildren due to parental separation or divorce, family feud, or a sudden event, such as relocation, affected the emotional well-being of grandparents (N = 442). Using data from the Longitudinal Study of Generations, the depressive symptoms of grandparents were tracked over 15 years. Growth curve analysis was used to compare grandparents who had lost contact with their grandchildren with those who had not and to examine preloss to postloss change in depressive symptoms. Grandparents who lost contact with their grandchildren experienced a steeper increase in depressive symptoms as they aged compared with other grandparents. Depressive symptoms of grandparents who lost contact because of a sudden event increased up to 3 years following the loss but returned to equilibrium thereafter. The authors conclude that grandparents who lost contact with their grandchildren experienced a negative impact on their emotional health. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Health psychology and scientific consensus: The case of depression and cardiovascular disease.

Science proceeds, directly or indirectly, by consensus. Obtaining scientific consensus proactively when investigating the impact of depression on cardiovascular disease has been daunting, as the professions interested in this area include health psychology, psychiatry, cardiology, epidemiology, and others. Whereas consensus is at times difficult when sought within one specialty, it is almost inconceivable when attempted across disciplines. Therefore, we applaud a new trend, as the National Heart, Lung, and Blood Institute recently called for a working group to provide recommendations on the assessment and treatment of depression in patients with cardiovascular disease. The publication of this working group's report signals two important landmark accomplishments. First, it offers concrete recommendations for researchers interested in contributing to this field. Second, and perhaps more important, the publication of this report signifies a process through which interdisciplinary research areas can be proactive in fostering scientific consensus. Health psychology, an area and a field of research that is naturally interdisciplinary, may be one of the key benefactors of joining and creating stronger consensus processes for this type of science. Whether health psychologists will play a role in creating opportunities to promote consensus in areas of scientific interest remains to be seen. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Recovery from major depressive disorder among female adolescents: A prospective test of the scar hypothesis.

This study examined the psychosocial consequences of experiencing major depressive disorder (MDD). In a 7-year longitudinal study of 496 female adolescents, the authors identified 49 girls who experienced their first episode of MDD and then recovered. They were compared with a randomly selected group of 98 never depressed participants on 13 psychological, social, psychiatric, and life events variables. None of the variables fit the scar pattern (i.e., a group difference that emerges during the first MDD episode and remains elevated post-recovery). All 13 variables were elevated before, during, and after the MDD episode, although some increased during the MDD episode. Results provide little support for the scar hypothesis among adolescent girls but instead suggest that many risk variables are elevated before and after the MDD episode. Interventions that modify these factors may help to reduce depression incidence and recurrence among female adolescents. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Reward sensitivity in depression: A biobehavioral study.

The approach-withdrawal model posits 2 neural systems of motivation and emotion and hypothesizes that these systems are responsible for individual differences in emotional reactivity, or affective styles. The model also proposes that depression is characterized by a deficit in reward-seeking behavior (i.e., approach motivation) and is associated with a relative decrease in left frontal brain activity. The authors tested aspects of this model by comparing the electroencephalogram alpha power of depressed and nondepressed individuals during a task that manipulated approach motivation. The study found that control participants and individuals with late-onset depression exhibited the hypothesized increase in left frontal activity during the approach task but individuals with early-onset depression did not. This suggests that early-onset depression may be associated with a deficit in the hypothesized approach motivation system. (PsycINFO Database Record (c) 2010 APA, all rights reserved)